Political institutions are part of it, but probably not the most important part. The excellent book Guns, Germs, and Steel[1] lays out very well researched reasons for the disparities we see today. Highly recommended reading!
Spoiler: What kind of crops and livestock you have paired to your climate over history is a big factor (number of calories you can raise per acre). What kind of livestock you had or didn't have also relates to what kinds of diseases might wipe you out (see Aztecs). And what kinds of raw materials you have available impacts what kind of commerce you can engage in. These factors over time have a huge impact on how civilizations advanced relative to each other.
There's a summary of the book on Wikipedia[2], along with some interesting criticisms.
Spoiler: What kind of crops and livestock you have paired to your climate over history is a big factor (number of calories you can raise per acre). What kind of livestock you had or didn't have also relates to what kinds of diseases might wipe you out (see Aztecs). And what kinds of raw materials you have available impacts what kind of commerce you can engage in. These factors over time have a huge impact on how civilizations advanced relative to each other.
There's a summary of the book on Wikipedia[2], along with some interesting criticisms.
[1] https://www.amazon.com/Guns-Germs-Steel-Fates-Societies/dp/0... [2] https://en.wikipedia.org/wiki/Guns,_Germs,_and_Steel